Solution-Mediated Growth of Two-Dimensional SnSe@GeSe Nanosheet Heterostructures

Nanosheet heterostructures that directly interface multiple distinct metal chalcogenides are important two-dimensional materials with unique synergistic properties. Solution routes to these materials offer potential advantages over existing vapor deposition and exfoliation/restacking methods, but they remain difficult to implement and control. Here, we show that SnSe can be grown in solution on micrometer-sized GeSe nanosheets and establish guidelines for achieving controllable deposition. Heating GeSe nanosheets in oleylamine with various amounts of SnCl₂ and TOP-Se reveals distinct regimes that favor growth of SnSe on the edge sites vs basal planes of GeSe. Using continuous injection to better control concentrations and reagent delivery, SnSe can be grown on GeSe to produce two distinct types of crystallographically aligned SnSe@GeSe nanosheet heterostructures.